X-Recipient: archive-cygwin@delorie.com X-SWARE-Spam-Status: No, hits=0.5 required=5.0 tests=AWL,BAYES_50,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,HS_INDEX_PARAM,RCVD_IN_DNSWL_NONE,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: sourceware.org Message-ID: <17333.86946.qm@web25506.mail.ukl.yahoo.com> Date: Mon, 27 Sep 2010 08:03:42 +0000 (GMT) From: Marco Atzeri Subject: Update graphicsmagick with quantum depth = 16 To: cygwin@cygwin.com MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com Dear users, I am thinking to update GraphicsMagick-1.3.12 moving from "quantum depth =3D 8" to "quantum depth =3D 16" following a discussion on octave bug list http://savannah.gnu.org/bugs/?30715 about the improved image quality using the higher quantum depth, specially for medical and scientific images. For details about the difference http://www.graphicsmagick.org/INSTALL-unix.html ------------------------------------------------------------- Larger pixel quantums cause GraphicsMagick to run more slowly and to requir= e more memory. For example, using sixteen-bit pixel quantums causes Graphic= sMagick to run 15% to 50% slower (and take twice as much memory) than when = it is built to support eight-bit pixel quantums. The amount of virtual memory consumed by an image can be computed by the eq= uation (QuantumDepth*Rows*Columns*5)/8. This is an important consideration = when resources are limited, particularly since processing an image may requ= ire several images to be in memory at one time. The following table shows m= emory consumption values for a 1024x768 image: QuantumDepth Virtual Memory 8 3MB 16 8MB 32 15MB GraphicsMagick performs all image processing computations using double-prec= ision floating point so results are very accurate. Increasing the quantum s= torage size decreases the amount of quantization noise (usually not visible= at 8 bits) and helps prevent countouring and posterization in the image. ------------------------------------------------------------ Anyone having problem with it ? Of course I will update octave to use this improvement. Regards Marco Atzeri=20 -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple